I am not a Line 6 repair shop, so if this is a warranty situation, as far as I know, Dan over at Music Manor in Lansing is a Line 6 shop.
Line 6 as a company does not issue schematics or sell parts to anyone but their own authorized warranty repair shops for their brand. SO independent shops like mine have to rely on what schematics are scattered on the internet. Having said that, many many repairs do not even require a schematic. If your output power IC is blown, I can swap out an LM3886 or TDA7293 or whatever it is, as could any other competent repair shop.
If you would like to bring your amp by my shop, I would be happy to give it a quick assessment. I do not charge for that.
Once we know just what it is that needs fixing, I can talk to you about it more knowledgably.
We work musician hours here, the shop opens by 6:30PM and we stay until after the clubs close. Call me at 882-2544 in the evening.